Cutting tool holding assembly

Abstract

A cutting tool holding assembly is arranged for rapid replacement of cutting tools on machine tools. The assembly includes an adaptor for locating a tool holder in a drive spindle. The adaptor has a base member which is secured in the spindle and a body member which is secured releasably to the base member. The tool holder is secured to the body member. The base member is secured in the base of a bore in the spindle and the body member is releasably secured against rotation relative to the spindle.

We claim: 
     
       1. A cutting tool assembly including a tool holder, a drive spindle with a central bore and an adaptor for locating the tool holder in the drive spindle, the adaptor comprising a base member arranged to be secured against removal from the spindle, a body member having first securing means for securing the body member releasably to the base member and second securing means for securing the tool holder to the body member, the base member being secured in the base of the bore of the spindle and the body member being releasably securable against rotation relative to the spindle, the base member being of two part construction having a first part secured in the base of said bore and a second part secured to the first part, the first and second parts having interposed between the parts resilient means whereby the parts are relatively movable in the axial direction of the spindle, wherein the resilient means is arranged to urge the second part in a direction towards the base of the bore, and further comprising stop means whereby the extent of said relative movement is limited in each direction. 
     
     
       2. An assembly according to claim 1 wherein the resilient means comprises spring means located between the first and second parts of the base member, the first part being secured in a fixed position in said spindle in use, the second part being movable relative to the first part under the restraint of said resilient means. 
     
     
       3. An assembly according to claim 1 wherein the body member carries a sleeve releasably engageable with the spindle to prevent rotation of the body member relative to the spindle when the body member is secured by said first securing means. 
     
     
       4. An assembly according to claim 3 wherein said sleeve is movable axially of the assembly and is resiliently biased towards said engagement position, the sleeve and the spindle comprising interengaging dogs. 
     
     
       5. An assembly according to claim 1 comprising location means for orienting the base member in the bore of the spindle relative to the axis of the assembly. 
     
     
       6. A cutting tool assembly including a tool holder, a drive spindle with a central bore and an adaptor for locating the tool holder in the drive spindle, the adaptor comprising a base member arranged to be secured against removal from the spindle, a body member having first securing means for securing the body member releasably to the base member and second securing means for securing the tool holder to the body member, the base member being secured in the base of the bore of the spindle and the body member being releasably securable against rotation relative to the spindle, the base member being of two part construction having a first part secured in the base of said bore and a second part secured to the first part, the first and second parts having interposed between the parts resilient means whereby the parts are relatively movable in the axial direction of the spindle, wherein said first securing means secures the body member to the second part of the base member and said second part includes a nose portion which is engageable with a seating formed in the body. 
     
     
       7. An assembly according to claim 6 wherein the nose portion and the seating define between them cam surfaces and the body is secured to the nose portion by relative rotational movement between the body and the base member to draw the body member towards the base member against the action of said resilient means. 
     
     
       8. An assembly according to claim 6 wherein the seating includes an entry portion and a locking portion, and the nose portion of the second part of the base member is located in the entry portion and then secured in the locking portion by relative rotation of the body member and the base member. 
     
     
       9. A cutting tool assembly including a tool holder, a drive spindle with a central bore and an adaptor for locating the tool holder in the drive spindle, the adaptor comprising a base member arranged to be secured against removal from the spindle, a body member having first securing means for securing the body member releasably to the base member and second securing means for securing the tool holder to the body member, the base member being secured in the base of the bore of the spindle and the body member being releasably securable against rotation relative to the spindle, the base member being of two part construction having a first part secured in the base of said bore and a second part secured to the first part, the first and second parts having interposed between the parts resilient means whereby the parts are relatively movable in the axial direction of the spindle, and further comprising radially outwardly movable members carried by the first part of the base member which are selectively engageable with the walls of the bore of the spindle whereby the base member is secured in the bore in the spindle.